12999921 has 16 divisors (see below), whose sum is σ = 19008768. Its totient is φ = 7837200.

The previous prime is 12999919. The next prime is 12999929.

12999921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 12999921 - 2¹ = 12999919 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12999929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6030 + ... + 7896.

It is an arithmetic number, because the mean of its divisors is an integer number (1188048).

Almost surely, 2^12999921 is an apocalyptic number.

12999921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12999921 is a deficient number, since it is larger than the sum of its proper divisors (6008847).

12999921 is a wasteful number, since it uses less digits than its factorization.

12999921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2092.

The product of its digits is 26244, while the sum is 42.

The square root of 12999921 is about 3605.5403201185. The cubic root of 12999921 is about 235.1329924751.

The spelling of 12999921 in words is "twelve million, nine hundred ninety-nine thousand, nine hundred twenty-one".